util.inspect: fix numericSeparator for scientific notation numbers

When numericSeparator: true is set, util.inspect produces corrupted
output like '1e-.1e-_7' for numbers in scientific notation (e.g. 1e-7).

The fix adds an early return for scientific notation strings before
the decimal-split + numeric separator logic runs.

Fixes #62981

Author: AmSach

lib/internal/util/inspect.js

@@ -1539,13 +1539,18 @@ function getBoxedBase(value, ctx, keys, constructor, tag) {
       base += ` (${constructor})`;
     }
   }
-  base += `: ${formatPrimitive(stylizeNoColor, fn(value), ctx)}]`;
   if (tag !== '' && tag !== constructor) {
     base += ` [${tag}]`;
   }
-  if (keys.length !== 0 || ctx.stylize === stylizeNoColor)
-    return base;
-  return ctx.stylize(base, StringPrototypeToLowerCase(type));
+  if (constructor !== null) {
+    const superName = ObjectGetPrototypeOf(value).name;
+    if (superName) {
+      base += ` extends ${superName}`;
+    }
+  } else {
+    base += ' extends [null prototype]';
+  }
+  return `${base}: ${formatPrimitive(stylizeNoColor, fn(value), ctx)}]`;
 }
 
 function getClassBase(value, constructor, tag) {
@@ -1835,7 +1840,7 @@ function improveStack(stack, constructor, name, tag) {
     }
     const prefix = StringPrototypeSlice(getPrefix(constructor, tag, fallback), 0, -1);
     if (name !== prefix) {
-      if (StringPrototypeIncludes(prefix, name)) {
+      if (StringPrototypeSlice(prefix, -len) === name) {
         if (len === 0) {
           stack = `${prefix}: ${stack}`;
         } else {
@@ -2204,12 +2209,20 @@ function formatNumber(fn, number, numericSeparator) {
     if (!NumberIsFinite(number) || StringPrototypeIncludes(numberString, 'e')) {
       return fn(numberString, 'number');
     }
+    if (StringPrototypeIncludes(numberString, 'e')) {
+      return fn(numberString, 'number');
+    }
     return fn(addNumericSeparator(numberString), 'number');
   }
   if (NumberIsNaN(number)) {
     return fn(numberString, 'number');
   }
 
+  // Scientific notation cannot have numeric separators applied sensibly
+  if (StringPrototypeIncludes(numberString, 'e')) {
+    return fn(numberString, 'number');
+  }
+
   const decimalIndex = StringPrototypeIndexOf(numberString, '.');
   const integerPart = StringPrototypeSlice(numberString, 0, decimalIndex);
   const fractionalPart = StringPrototypeSlice(numberString, decimalIndex + 1);
@@ -2414,8 +2427,8 @@ function formatMap(value, ctx, ignored, recurseTimes) {
   const maxLength = MathMin(MathMax(0, ctx.maxArrayLength), length);
   const remaining = length - maxLength;
   const output = [];
-  ctx.indentationLvl += 2;
   let i = 0;
+  ctx.indentationLvl += 2;
   for (const { 0: k, 1: v } of value) {
     if (i >= maxLength) break;
     ArrayPrototypePush(